Tuesday, June 12, 2012

Manuka honey from New Zealand is often considered a
medicinal product of special value due to its high level of antimicrobial
activity. Therefore, the distinct authentication of its botanical origin is of
great importance.

In this respect, it is particularly the analysis especially
phenolic acids, flavonoids, and norisoprenoids which are described as useful
aside of the common pollen analysis.

In the present study numerous manuka honeys were analysed by
UPLC-PDA-MS/MS after solid phase extraction and compared to other kinds of
honey in order to define marker substances characteristic for manuka honeys.

The PDA-profiles obtained notedly differed from each other
so that individual honey samples could be assigned to three groups.

In this, typical for the honeys of Group 1 were the
comparably high concentrations of 4-hydroxybenzoic acid, dehydrovomifoliol, and
benzoic acid whereas the profiles of

Group 2 showed high kojic acid and 2-methoxybenzoic acid
intensities.

Characteristic for the manuka honeys of Group 3 were high
syringic acid, 4-methoxyphenyllactic acid, and methyl syringate yields.
Furthermore, the comprehensive comparison of manuka honeys to other unifloral
honeys revealed that especially kojic acid, 5-methyl-3-furancarboxylic acid,
3,4,5-trimethoxybenzoic acid esterified with maltose, unedone, 2-methoxybenzoic
acid, 4-methoxyphenyllactic acid,
3-hydroxy-1-(2-methoxyphenyl)-penta-1,4-dione, and methyl syringate are useful
for distinguishing manuka honeys from the other kinds of investigated honey.

Moreover, kojic acid, unedone,
3-hydroxy-1-(2-methoxyphenyl)-penta-1,4-dione, 5-methyl-3-furancarboxylic acid,
3-hydroxy-1-(2-methoxyphenyl)-penta-1,4-dione, and lumichrome were identified
in manuka honey for the first time.